I have first initial / last name at gmail for a common Irish name. My wife has first name last name.
There’s about a dozen people who routinely use my email address. The Washington post let someone subscribe for a year without any validation. One dude lost a job offer because they couldn’t contact him. One woman was the general manager of a factory and emailed “herself” with a VPN client and excel spreadsheet with passwords to access the factory’s IT and SCADA systems. A detective sent crime scene videos. The most recent is a guy in Scotland who isn’t paying his electric bill.
My wife had someone who has stolen her accounts via retail employee resets at CVS, Sephora and others. She’s an executive at a big wall st bank, and spends a lot on makeup - my wife got lots of points when she reset the Sephora account back.
I have a common lastnameinitial @ email provider. It's the same username from my mainframe days. Some people with similar surname use that, probably because they either don't want to receive emails or because they are just... I don't know, clueless?
Usually I takeover an account and change the password. Then add a 2FA if possible and update the details to my name and address. This way people can't say it's their account anymore.
A couple of times there were credit card numbers. I just delete those if possible.
I have cancelled hair appointments and car services. I have received flight information multiple times. I have locked out an account on a French dating site, which had some interesting exchanges (the guy's missing out!).
I did not cancel a vet appointment. Pets need to see a vet and their owners being dumb is not an excuse. I won't interfere with that. But I did book a full grooming for a week after.
When I takeover I just use a random password from Bitwarden and don't even bother saving the account, as I don't plan to ever use these again.
Generally speaking, it seems people gets it wrong when things are created over phone etc.
My firstname lastname is not common, but if one use firstname.middlenameinitial.lastname you can be sure that several people when noting their email will skip the initial, same if you have a suffix.
I had banks, credit cards, social securities related stuff being registered to my email, generally it last a few weeks to be fixed.
I have lastname first initial @ gmail, and I wish I didn't. I have started using it for school related stuff for my kid, and other places where I want to present as normal, but mostly I get garbage from a set of about 4 people who share my last name and first initial, but don't know their email address (I don't know it either!).
Lots of car dealers and travel reservations. Ugh. I've got a couple job application responses, and usually get a nice email from the sender when I respond and let them know the email was misdirected.
I used to get a lot of mail directed to people whose organization's domain has an extra letter compared to mine, but I think they must have figured it out, or closed down, I used to add their mistaken addresses to be rejected if sent to and have to update when they got a new employee (their IT person sent me the new user stuff once sigh), but that stopped happening. I got some invoices for them that looked kind of shady, but they're in Brazil, and I can't navigate the system down there to have forwarded it to someone who would find it interesting.
Are you "john.smith@gmail.com" or something like that?
I'm firstname@firstnamelastname.com, and I have had maybe a half dozen instances in the past decade.